Lock washer



June 19, 1934. C; G, QLSON 1,963,800

LOCK WASHER Filed Feb. 27. i953 Patented June 19, 1934 PATENT OFFICE1,963.8 l Loox wssnnn Carl G. Ison, Chicago, lll., assignor to IllinoisTool Works, Chicago, lll., a corporation of Illinois ApplicationFebruary 27, 1933, Serial No. 658,738

8Claims.

My invention relates generally to locking devices and particularly tolocking devices or washers of the pronged type, namely, the typeprovidedwith radial prongs along one margin of an annular body.

, One of the primary objects of my invention is to provide a lockingdevice of improved practical construction, which may be readily formedfrom fiat spring stock.

More specically, my invention contemplates the provision of, a lockingdevice equipped with warped prongs which are conflgurated in a novelmanner so as to improve the locking characteristlc thereof, and to thisend I propose to so shape 35 and warp theprong that a curved lockingedge will project above and below the plane of the washer body so as toaggressively engage the work piece and the surface of a nut or screwhead to thereby positively secure said parts against relative movement.

Still more specifically, my invention contemplates the provision ofVprongs provided along at least one of an annular body of fiat stock,which prongs are so warped, twisted, or flexed 2 out or the plane of thebody to present edges which partake of a reverse curvature in extend ingfrom the body to thev free extremity of the prong. v I A further o bjectof my invention contemplates 3 the provision of a locking device, as setforth above, in which the locking edges of the prongs projecting onopposite sides of the washer body are so curved that the portion of theedge in the vicinity ofthe free extremity of the prong is tangent to aune parallel with the piane or the washer body, and in this manner Ipresent locking edges asdistinguished from sharp work en- Sling corners,said edges extending over a radial distancewhich is suicienttoeffectively resist .retrograde movement of the screw head or nut clampedthereagainst.

,'YIt has been found that in someinstances a flocking edge, asdistinguished from a sharp work engaging corner,`is preferable. Sharpwork en- 5 gaging corners have`a tendency to mill a groove in the-work.This is particularly true in instances where a nut or screw head must beloosened from time to time. When the nut is loosened by the applicationof considerable force,

5 the sharp work engaging corners of the prongs in opposing retrogrademovement causes a groove of V-shaped crosssection to'be milled or formedupon the clamping surface.

It is an. object of my invention to provide a 5 locking edge which willnot produce the above mentioned milling or grooving effect, and to thisend I propose to produce a locking edge which does not extend over thegreater portion of the radial length of the prong,.but which, due to itscurvature, will imbed itself within the work with, an effectivenessequal to or greater than a straight locking edge of greater length.

The vforegoing and numerous other objectsand advantages will be moreapparent from the following detailed description when considered in.connection with the. accompanying drawing,

wherein- Figure 1 is a plan view of a locking device or washerconstructed in accordance with the teachings of my invention; f

Figure 2 is a transverse sectional view taken substantially along theline 2-2 of Figure 1, a work piece and nut being indicated by dottedlines in operative association with the washer;

' Figure 3 is an enlarged view of the prong shown 75 at the left side ofFigure 2;

Figure 4 is similarly an enlarged fragmentary view of the central prongof Figure 2, said view being taken along the line 4 4 of Figure 1;

Figure 5 is an enlarged plan view of the prong 8 shown in Figure 4;

Figure 6 is a fragmentary plan view of a washer provided with myimproved prong construction Aalong the outer margin of the body, asdistinguished from the internal tooth constructionshowninli'igures1and2;and Figure 7 is a-plan view of an electricalterminal which is lprovided at one extremity with my improved prongconstruction.

Referring now tothe drawing more in detail wherein like numerals havebeen employed to designate similar parts throughout the various figures,it will be seen that my invention contemplates a locking device orwasher, which includes an annular body 10 and a plurality of radial 95prongs 12 formed and spaced along the inner margin thereof (see Figures1 to 5, inclusive). It will be seen that each of the prongs 12 is warpedor twisted in such a'manner as to present work eni gaging' edges 14 onopposite sides of the plane of 100 the washer body 10. Each prong issubstantially rectangular in cross section and is preferably of slightlygreater thickness at the root than atthe free extremity thereof.However, the taper of the tooth is very slight.

It will be observed that the edges 14 (see particularly Figure 3)partake of a reverse curvature. That is to say, the outer portion of theedge, namely, the portion A positioned toward the free end of the prong.has a curvature reverse to the. 110

curvature o the edg'e where it joins the body iii, namely, the portionB. It will m seen that the work engaging portion A (Figure 3) of theedges 14, positioned in the vicinity of the free extremity of the prong,is tangent at its outermost point to 4a. line 16, and this line issubstantially parallel with the plane of thev washer body 10. Theportion B (Figure 3) of the curvature positioned at the root of theprong is tangent to a line 18 which is coincident with the plane, whichincludes one of the bounding surfaces oi the body is.

The portion A of each edge i4 is adapted to lmbed itself withintheclamplng surface oil the nut 19 and work piece 21 in a very eiilecwtive manner. The curvature of this portion A materially assists incausing the edge to more readily imbed itself'than a straight edge ofequal or greater length. In other words, ii the edge 14 were straightover a greater portion of the radial length of the prong, it wouldrequire greater clamping force to cause said edge to imbed itself thanwhen the relatively short curved section A is employed. The action ofthe portion or section A upon the adjacent surface of the work or nutdiiers materially from the action of a sharp work engaging corner. Thatis to say, ii the line 14 of Figure 3 curved out of the plane of 'thewasher body until it terminated at the free end of the prong, a sharpthree-sided corner would be presented. Such a corner, while it readilyimbeds itself within the work and nut and serves to secure the partsagainst relative movement. has a tendency in some instances to cause agroovel of V;- shaped cross section to be formed or milled within thesurface of the nut. 'I'his is particularly true when the washer is usedin combination with a nut orscrew head which must from time to time beloosened for purposes of replacement or repair. In loosening the nut orscrew, the opposition afforded by the sharp work engaging corner issufilcient to cause a groove to be formed. Then, when the nut or screwis again applied to the washer, the locking effectiveness of the teethis materially reduced. By employing prongs of my improved construction,wherein a relatively short but effective section of a curved edgeprojects out of the plane' of. the washer body, this milling or groovingaction is materially reduced without impairing but rather increasing thelocking effectiveness ofthe prong.

The cross section of the prong is substantially rectangular, and aneffective strutting action. as indicated by the dot-and-dash line inFigure 4,

takes place between the oppositely 'disposed edge sections A. It willbeA apparent that the invention is not limited to the washer shown inFigure 1, wherein the teeth or prongs are provided along the innermargin, but is also capable of application in the type of washer shownin Figure 6, wherein prongs I12a are provided along the external marginof an annular body portion 10a. Likewise, my improved prong constructionmay be used on devices, such as theelectrical terminal 20 shown inFigure 7. This terminal includes a body portion 23 and is provided atone extremity with an aperture 24 for receiving the free end of anelectrical conductor. and is formed at its opposite end with a pluralityof prongs 12b, which correspond structurally with the prongs 12 shown inFigures 1 to 5, inclusive.

From the foregoing it will be apparent that my washer presents a markedimprovement over washers of this general type which have been employedheretofore, in that the arrangement of the work engaging edges is suchas to present a curvd 'claim as new and desire to secure by LettersPatent is:

l. i locking device including an annular body portion formed from datspring stock and a pluf rality of radially extended prongs providedalong 'at least one margin thereof, said prongs being warped so as topresent radially disposed work engaging edges on opposite sides of theplane of the body portion, the sections of said edge in the vicinity ofthe free extremity of the prong being curved and providing an effectivelocking medium when'clamped between two surfaces.

2. A locking device including an annular body IBG portion formed fromfiat spring stock and a plurality of prongs provided along at least onemargin thereof, said prongs being warped so as to present work engagingedges on opposite sides of the plane o! the body portion. the sectionsof said edge in the vicinity of the free extremity of the prong beingcurved and providing an eiective locking medium when-clamped between twosurfaces.4 said curved portion having a length which fis not greaterthan half the radial length of the prong. Y

3. A locmng device including an annular body portion'iormed from :datspring stock and a plu rality of radially'extended prongs provided along-at least one margin thereof, said prongs being warped so as to presentradially disposed work enssins edges on opposite sides of the plane of-the body portion, the sections of said edge in the vicinity o! the freeextremity of the prong being curved and providing an effective lockingmedi- `121i um when clamped between two surfaces, one point on saidcurved section being coincidentl with a tangent parallel with and spacedfrom the plane of the body.

4. A locking device including anannular body 125 portion formed from atspring stock and a plurality of radially extended prongs provided alongat least one margin thereof, said prongs being warped so as to presentradially disposed work engaging edges on opposite sides of the plane ofthe body portion, each edge including sections curved in oppositedirections, one of said section: being located in the vicinity ofthefree extremity ofthe prong in position to lockingly engage a work piecewhen clamped thereagainst.

5. A locking device including an annular body portion formed from ilatspring stock and a plurality of radially extended prongs provided alongat least one margin thereof,L said prongs being warped so as to presentradially disposed work engaging edges on opposite sides oi' the planeof. the body portion, said edge including sections curved in oppositedirections, one of said sections being located in the vicinity of thefree ex-` tremity of the prong in position to lockingly engage a workpiece when clamped thereagainst, another portion oi' said -curved edgein the vicinity of the root of the prong blending with one of thebounding surfaces of the body portion. 1

6, A )NUDE device including an annular body 15.`

portion formed from at spring stock and a plurality of radially extendedprongs provided along' at least one margin thereof, `said prongs beingwarped so as to present radially disposed work engaging edges onopposite sides of the plane of the body portion, said edge includingsections curved in opposite directions, one of said sections beinglocated in the vicinity of the free extremityjof the prong in positionto lockingly engage a work piece when` clamped thereagainst, a point onsaid last mentioned curved section being tangent to a line parallel toand spaced from the plane of the washer body.

7./A locking device including an annular body portion formed from flatspring stock and a plurality of prongs provided along at least onemargin thereof, said prongs being warped so as to present work engagingedges on opposite sides of the plane of the body portion, each edgeincluding sections curved in'opposite directions, one of said sectionsbeing located in the vicinity of the free extremity of the prong inposition to lockingly engage a work piece when clamped thereagainst,another portion of said curved edge in the vicinity of the root of theprong blending with a tangent coincident with a plane which includes oneof the bounding surfaces of said body portion.

8. A locking device including an annular body portion formed from flatspring stock and a plurality of radial prongs spaced along at least onemargin thereof, said prongs being 'twisted from their roots to theirfree ends so as to present work engaging edges on opposite sides of theplane of -the body portion, the sections of each edge in the vicinity ofthe free extremity of the prong being curved and providing aneifectivelocking medium when clamped between two surfaces.

CARL G. OISON.

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